Actuating valve with opposed unequal areas



Patented Nov. 16, 1948 2,453,812 ACTUATING VALVE wrrn orrosnn T oi-rice UNEQUAL AREAS Hubert s. Phelan, Berkley. Mich., asslgnor to Chrysler Corporation, Highland Park, Mich., a

corporation of Delaware Application May is. 1944, Serial No. 535,804

3 Claims. Cl. 121-38) This invention relates to a device responsive to a condition, such as pressure, for establishing one condition or another, such as a high speed ratio or a low speed ratio in a transmission. More speciflcally, it relates to a device for shifting in response to atmospheric pressure 'a transmission drivingly connecting a supercharger with an englne supplied by the supercharger.

It is known to drive a supercharger from an engine by means of a transmission having a lowspeed ratio for driving the supercharger at an atmospheric pressure higher than a certain value and a high-speed ratio for driving the super-' charger at'an atmospheric pressure lower than a certain value. This arrangement is employed so that there may be obtained without higher engine speed the higher supercharger speed requisite for maintaining a certain delivery pressure to the engine in spite of lower atmospheric pressure. When the engine is employed as part of an aircraft power plant, the change in atmospheric pressure will in general be due to change in altitude. It is theoretically desirable that the shifting of the transmission from low speed to high speed take place upon decrease of atmospheric pressure to a certain value or increase of altitude to a corresponding value, and the shifting from high speed to low speed, upon increase of atmospheric pressure to the certain value or decrease of altitude to the corresponding value. However, actual operation at or near the predetermined atmospheric pressure or altitude may produce a condition of hunting" that is common to governors operating upon a certain value of a condition. In other words, the atmospheric pressure and altitude at which a plane flies may decreaseand increase from the predetermined values, although the pilot is attempting to maintain a certain altitude, and so the transmission willcontinually be shifted from one speed ratio to the other and back again. This is undesirable.

I have overcome this difliculty by making arrangements so that the transmission is shifted from low speed to high speed at a certain value of atmospheric pressure and is shifted back to a low speed at a definitely greater value of atmospheric pressure. In terms of altitude this means that the shift from low speed to high speed takes place at one altitude, and the shift backto low speed at a definitely lower altitude. Thus, if the plane is flying generally at a certain altitude, there may be a shift of the transmission either from low speed to high speed or from high speed to low speed, but there will be only one shift whatever it is.

An object of the present invention-is to provide an improved means for causing an actuator to establish one conditon or another in response to the existence or arising of a predetermined value of pressure. This may involve a valve arranged to pass pressure fluid for the establishment of one condition and to block the passage of pressure fluid for the establishment of another condition.

Another object is to provide an improved means for shifting a transmission in response to a predetermined value of pressure. The transmission may be a driving connection between an engine and a supercharger supplying the engine and may shift upon arrival of a certain value of atmospheric pressure dependent upon altitude.

A further object is to provide an improved valve adapted to shift a transmission by blocking or unblocking the passage of pressure fluid. The arrangement may be such that passage of fluid by the valve to an actuator for the transmission will cause the shift from one speed ratio to another speed ratio and the blocking of the fluid by the valve will cause the actuator to shift the transmission back to the said one speed ratio.

Other objects will appear from the disclosure.

The single figure of the drawing shows schematically and in section, the novel apparatus of the present invention.

A housing it in which is positioned a bellows ll comprising a corrugated element l2, a spring It and and members Ml and IE. is provided. The end member It has a threaded extension l8 engaging a threaded opening in an end plate ll of the housing Ill. The threaded extension It has in its end a slot I8 for reception of a tool such asa screw driver by which the end member It may be adjusted with respect to'the end plate H. A lock nut it engages the threaded extension IS. The end member H has a tubular extension 20 receiving in telescoping relation an extension 2! on the end member l5. Engagement of the tubular extension 20 with the end member I! as shown in the drawing limits the collapse of the bellows H. The end member l5 also has an extension 22 receiving a rounded enlarged portion 23 of a piston valve 24. The rounded enlarged portion 23 fits in a rounded enlargement 25 in the extension 22 and with the enlargement forms a universal connection between the piston valve 24 and the end member ii. The piston valve 24 has a small piston section 28 and a large piston section 21 spaced from the section .28. The piston sections 26 and 21 are Joined by a rod-like portion 2!, and the enlarged portion 23 andthe piston section 28 are @tion sleeve valve ing to the engine 82.

joined by a rod-like portion 28. The piston valve has a small bore 8| receiving the small piston sec- 28 and a large bore 82 receiving the large piston section 21. The sleeve valve 88 also has an external annular groove 88 from which extend a plurality of peripherally spaced ports 84 providing communication between the groove 88 and the large bore 82. annular groove 88 from which extend peripherally spaced ports 88 providing communication between the groove 88 and the enlarged bore 82. A relief opening 81 extends from the small bore ii in the shoulder 88 formed shoulder 88 is formed on valve 88, and on the shoulder is mounted a cap 48 serving as a cam follower engaging a cam 4| shown only in part and having at the right end thereof. "A

ably mounted in a sleeve 48 fixedly mounted in a bore provided in a portion .44 of the housing II. The right end of the sleeve 48 has an inwardly directed flan e 48. flange 48 and the shoulder 88 to maintain'the follower 48 in engagement with the cam 4|. One side of the sleeve 48 is provided with an external groove 41. An opening 48 extends from the groove 41 to the interior of the sleeve at a point directly opposite the groove 88. A passage 48 formed in the housing l8 communicates with the groove 41. A pressure line 88 is connected to the passage 48. A drain line 8| is connected to an opening 82 communicating with the chamber in the housing ill in which the bellows II is mounted. An opening 88 is formed in one side of the sleeve 48 at a point opposite the groove 88. A passage 84 is formed in the extension 44 of thehousing III in communication with the opening 88, and a line 88 has threaded engagement with the passage 84. The line 88 terminates in a threaded fitting 86 having threaded engagement with an opening 81 in an end part 58 secured to a cylinder 88. Mounted within the cylinder 88 is a piston valve 88 having spaced piston sections 6i and 82 and a g 63 joining the sections reduced rod-like section 8| and 82. 'The piston section 82 has a bore in which is positioned a spring 84 and balls 88 urged outwardly by the spring 64 into engagement with an annular groove 88 formed within the hereof the cylinder 89. The spring 84, the balls 88, and the groove 86 constitute a detent mechanism tending to hold the piston 60 in the position shown. The left end of the cylinder 88 is provided with a closure portion 81 in which extends a relief opening '88. A spring 68 acts between the piston section 6| and the closure portion 81 to urge the piston valve 88 to the right. The cylinder 88 is provided with a drain opening 18 communicating with a drain opening 1| formed in a support member 12 upon which the cylinder 88 is mounted. The cylinder 89 also has an opening 18 registering with an opening 14 in the support 12 .to which is connected a pressure line 18. The cylinder 88 is also provided with an opening 18 registering with an opening 11 formed in the support 12, and a line 18 leads from the opening 11 to a transmission 18 adapted to drive a supercharger 80 from an engine-driven shaft 8| leading from an engine 82. The supercharger 88 may be either of the axial type or of the radial type and is shown to have an inlet 88 for a' combustion supporting gas such as air, which it compresses and discharges into a delivery line 84 lead- The transmission 18 has a 88 to the exterior of the valve at a A spring 48 actsbetween the 24 is slidably mounted in a sleeve valve 88, which ,The sleeve valve "also has an plurality of speed ratios so that the supercharger 88 may be driven either at a high speed or at a low speed for a given speed of the engine-driven shaft 8 l The transmission 18 may be of the type shown in the patent to King, No. 2,248,240 dated July 8, 1941 and is adapted to operate at a high speed ratio when fluid under pressure is supplied to it through the line 18 and to operate at a'low speed ratio when no fluid is supplied through the line 18.

As in the construction of the patent, the transmission 18 is of the continuously draining type and so a drain 88 for the transmission is shown.-

the left end of the sleeve 7 a center'of r0-' tation at a point'42. The sleeve valve 88' is slid-- be somewhat different from atmospheric pressure 1 The bellows ll contains'a vacuum or a reduced pressure and is to pressure communicated to it through an opening 88 formed in the housing l8. The passage 88 may also be connected with some sort of scoop, not

shown, that will supply to the'bellows II a pressure comparable tov the pressure supplied to the supercharger 88 through the inlet 88, which may because of a ram eflect. As the atmospheric pressure decreases with increase in altitude of a plane in which the engine andsupercharger are mounted, the bellows ll expands causing movement of the end member l8 to the left. This movement is communicated to the piston valve 24 and after this piston valve moves sufficiently to the left, the large piston section 21 will have uncovered the ports 84 so that fluid under pressure supplied through the line 88 and reaching the ports 84 may pass across the rod-like portion 28 through the ports 86, the annular groove 88, the opening 88, and the passage 84 into the line 88. The pressure fluid passes from the line 88 into the right end of the cylinder 88 causing the piston valve 88 to move to the left against the action of the detent mechanism and the spring 88. The piston valve 88 moves to the left until the opening 13 is uncovered by the piston section 8| and the openings 18 and 18 are placed in communication so that the fluid under pressure may flow from the line 18 past the reduced portion 68 and through the line 18 to the transmission 18. Flow of fluid into the transmission 18 causes a shifting of the transmission from a low speed ratio to a high speed ratio; the high speed ratio being required because of the reduction in pressure of the air supplied through the inlet 88 to the supercharger 88.

The piston sections 28 and 21 of the piston valve 24 have already been described respectively as small and large. Thus when fluid under pressure flows past the rod-like portion 28 or the piston valve 24 with uncovering of the ports 34 by the large piston section 21, it acts against a large annular end area of the piston section 21 and a small annular end area of the piston section 26.

.- Since these areas are unequal and are opposed,

, and complete the uncovering. The arrangement is that the bellows II will move the piston valve 24 at a certain predetermined pressure to a point of uncovering of the ports 84 and the action of the pressure fluid against the piston valve 24 is positive and tends to snap the valve to a position in which the ports 84 are completely uncovered.

be subjected to atmospheric takes place in thetransmission 'aesaeia' 7 When atmospheric pressure increases with de crease in altitudeof the airplane, the bellows ll for causing by action of the pressure fluid against The result isthat with decrease in atmospheric pressure the ports 34 are uncovered by the large piston section 21 at a certain predetermined value and are completely uncovered by the force tending to move the piston valve to the left, and the ports 34 are notagain covered until the atmospheric pressure has risen to a value definitely above the predetermined value. The advantage of this arrangement is that the plane may be flown at or near an altitude providing the prede termined value of pressure at which the transmission 19 shifts from a low speed ratio to a high speed ratio, and yet once the shift has taken place there will be no "hunting,ei'fect or in other words, the transmission will not be shifted continuously back and forth between the high speed ratio and the low speed ratio,-for a definitely lower atmospheric pressure is required for the transmission to be shifted back to the low speed ratio.

Any fluid trapped between the end portion 81 of the cylinder 59 and the piston section II may escape through the openings 68 and I0.

Lengthwise adjustment of the sleeve valve III provides an adjustment of the predetermined value of the atmospheric pressure at which the shift from low speed ratio to high speed ratio 19. For example, if the sleeve valve is moved to the left, then the piston valve 24 must move farther to the left than otherwise in order to cause the piston section 21 to uncover the ports 84. This is accomplished by a greater expansion of the bellows II which must be due to a lesser atmospheric pressure. Thus adjustment of the sleeve valve 30 to the left decreases the predetermined value of pressure at which the shifting of the transmission- 19 takes place. It will be evident that adjustment of the sleeve valve 30 to the right will increase the aforesaid predetermined value of atmospheric pressure, since then the piston valve 24 will have to move not so far to the left to cause the ports 34 to be uncovered by the piston section 21. The adjustment of the-sleeve valve 30 to the left or tothe right is effected by rotation of the cam 4i. The-cam ll moves the sleeve valve to the right by causing the engagement of a portion of the cam with the follower 40 which portion has a greater spacing from the center of rotation 42. The spring 46 moves the sleeve 30 to the left when the cam 4| is rotated to cause a, portion having less distance from the center of.

rotation 42 to contact the follower 40.

I claim: V 1. In combination. a member having an inter- 'mediate reduced portion and opposed areas of different size at the reduced portion, means tending to make an increase 'to a certain magnitude of the force applied in one direction to the member move the member in the said one direction to a certain position, means for supplying fluid under pressure to the reduced portion of the member upon its arrival in the said certain position after movement in the saidone direction the areas of different size the member to be shifted positively and suddenly in the said one direction from the said certain position and to be held from being shifted in the opposite direction to and beyond the said certain position until lowering of the force applied to the member to a value definitely lower than the said certain magnitude, an actuator shiftable to produce a change between first and second conditions, and means connecting the-actuator, and the member so as to cause the pressure fluid reaching the reduced portion ofthe member upon its assumption ofthe said certain position or' therebeyond in the'said one direction to pass the reduced portion and to act against the actuator for producing the shift from the first condition to the second condition and to cause the pressure fluid to be blocked from reaching the actuator by the member upon return of the membar in the opposite direction to the said certain position or therebeyond for producing a shift from thesecond condition to the first condition.

2. In combination a member having an intermediate reduced portion and opposed areas of different size at the reduced portion, means tending to. make an increase to a certain magnitude of the force applied in one direction to the mem ber move the member in the said one direction to a certain position, means for supplying fluid under pressure to the reduced portion of. the

member upon its arrival in the said certain position after movement in the said one direction for causing by action of the pressure fluid against the areas of different size the member to be shifted positively and suddenly in the said one direction from the said certain position and to be held from being shifted in the opposite direction to and beyond the said certain position until lowering of the force applied to the member to a value definitely lower than the said certain magnitude, an actuator shiftable to produce a change between first and second conditions, means connecting the actuator and the member soas to cause the pressure fluid reaching the reduced portion of the member upon its assumption of the said certain position or therebeyond in the said one direction to pass the reduced portion and to act against the actuator for producing the shift tween the large and from the first condition to the second condition and to cause the pressure fluid to be blocked from reaching the actuator by the member upon return of the member in the opposite direction to the said certain position or therebeyond, and a drain line associated with the member so as to cause the return of the member to blocking position to drain pressure fluid from the means connecting the actuator and the actuator for protions at the ends of the intermediate portion, a

sleeve valve having a relatively large bore fitting the large diameter portion of the piston valve, a relatively small bore fitting the small diameter portion of the piston valve, an inlet passage to the large bore, and a drain passage to the small bore, the inlet and outlet passages being so spaced from one another-in relation to the spacing besmall diameter portions of the piston valve as to cause uncovering and covering of the inlet passage by the large diameter portion to produce, respectively, covering and uncovering the drain passage by the small diameter portion, means for causing increase of force applied to the piston valve in a direction from the small diameter portion to the large diameter to a certain magnitude to move the piston valve in the said direction to a position producing a slight uncovering of the inlet passage by the large diameter portion of the piston valve, means for supplying pressure fluid to the inlet passage for causing the'slight uncovering or the inlet passage to admit pressure fluldto the intermediate portion of the piston valve and the'action oi the pressure fluidagainst the large and small areas to move the piston valve further in the said direction to a complete uncovering of the inlet passage. this action of the pressure fluid against the large and small areas preventing return 01 the piston valve in the opposite direction toand beyond the position of slight uncovering of the inlet passage until. reduction or the force applied tothe valve to a value definitely below the said certain magnitude, an actuator for producing a shift between first and second conditions, and a 2 conduit connected with the actuator and the sleeve and piston valves so as to pass to the actuator pressure fluid admitted to the intermediate portion of the piston valve through un- 5 covering the inlet passage and uncovering the drain passage tor-producing the shift from the second condition to theflrst condition. y

' HUBERT 8. PHELAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATEQ PATENTS Number Name Date 526,149 Farley Sept. 18, 1894 1,175,089 Turner Mar. 14, 1916 1,615,890 Stevens Feb. 1, 1927 1,886,003 Garrison NOV. 1, 1932 1,938,762 Haas Dec. 12, 1933 2,094,449 Forlchon Sept, 28, 193'! 2,229,345 Schotz Jan. 21, 1941 2,246,476 Wood June 17, 1941 5, FOREIGN PATENTS Number Country Date 188,556 Great Britain Feb; 12, 1920 507,460

Great Britain June 15, 1939 

